Method of manufacturing plated metal elements

ABSTRACT

A METHOD OF MANUFACTURING PLATED METAL ELEMENTS INCLUDING THE STEPS OF EXTRUDING AN ELEMENT INTO AN INERT ATMOSPHERE, WORKING THE METAL ELEMENT AS BY DRAWING THE SAME WHILE MAINTAINING IT IN AN INERT ATMOSPHERE TO PREVENT CHEMICAL CHANGES OF THE SURFACE MATERIAL THEREOF,   AND PLATING THE ELEMENT DIRECTLY AS IT IS DELIVERED FROM THE INERT ATMOSPHERE.

June 1,1971 w. D. KELLY EIAL 3,582,478

' METMon oF MANUFACTURING PLATED META1J ELEMENTS Filed Nov. 14, 1968 Nwm INVENTORS WILLIAM I D. KELLY WILLIAM o. KELLY JR,

- W BY /jk 77 ATTORNEYS.

United States lPatent O METHOD OF MANUFACTURING PLATED lMETAL ELEMENTS William D. Kelly, 12 Blodgett St., Clarendon Hills, Ill. 60514, and William D. Kelly, Jr., 1000 Waola, La Grange, Ill. 60525 Filed Nov. 14, 1968, Ser. No. 775,706 Int. Cl. B21c 23/22; B231) 17/00; C23b 5 /58 U.S. Cl, 204--28 14 Claims ABSTRACT OF THE DISCLOSURE A method of manufacturing plated metal elements including the steps of extruding an element into an inert atmosphere, working the rnetal element as .by drawing the same while maintaining it in an inert atmosphere to prevent chemical changes of the surface material thereof, and plating the element directly as it is delivered from the inert atmosphere.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to metal plating and in particular to manufacturing metal plated elements. t

Description of the prior art In ,one known method of manufacturing copper plated aluminum elements, the aluminum is lirstly chemically treated to remove the oxide coating normally formed thereon, immediately prior to the plating operation. The aluminum is then rstly plated with zinc or the like and then copper plated by substituting copper for the original plating metal. Such preparation operations are relatively expensive.

SUMMARY OF THE INVENTION The present invention comprehends an improved method of manufacturing plated elements eliminating the disadvantages of the known methods in a novel and simple manner. More specically, the invention comprehends a method of continuously forming plated elongated metal elements wherein the elements are extruded and delivered to the plating means through an inert atmosphere effectively precluding chemical changes in the surface of the metal elements thereby obviating the need for removal of such changed surface portions. Further, the invention comprehends the Working of the extruded elements in the inert atmosphere prior to the plating operation thereby to provide improved strength and other desirable characteristics.

More specilically, the invention comprehends a method of continuously forming a plated elongated metal element comprising the steps of extruding metal into a fluid which is substantially inert relative to the extruded metal, the metal |being extruded to define an elongated element, working the element While maintaining it in substantially inert fluid, delivering the worked element directly -from the inert fluid'into a plating uid, and causing the plating fluid to plate the element.

Still more specilically, the invention comprehends the provision of such a method wherein the working step com prises a step of drawing the element through a drawing die. The invention comprehends the concurrent extrusion of a plurality of such elements and subsequent concurrent working and plating of the plurality thereby to further reduce the cost.

Still more specifically, the invention is directed to manufacturing copper plated aluminum elements, such as wires or tubes, by extruding the aluminum elements into an inert atmosphere, drawing the aluminum elements Patented June 1, 1971 ice while maintaining them in an inert atmosphere and directly copper plating the drawn wires by passing lthem directly from the inert atmosphere into an electroplating fluid.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as disclosed in the drawing, a plated elongated metal element generally designated 10 is continuously formed in an apparatus generally designated 11. In illustrating the invention, the plated element may comprise a copper plated aluminum wire, it being understood that other suitable material may be employed and elements formed within the scope of the invention.

As shown in the drawing, the apparatus 11 includes an extruder generally designated 12, a drawing portion generally designated 13, and a plating portion 14. The apparatus 11 is shown schematically as specific constructions of the elements thereof are well known to those -skilled in the art and require no further description here. Thus, the extruder 12 comprises a conventional extruder having a pressure piston 15 arranged to extrude aluminum 16 through an extruder nozzle 17 in the lform of a wire 18. The aluminum 16 is maintained at a high temperature in the extruder 12 and is permitted to cool as it passes lfrom the extruder nozzle 17 to form the continuous wire 18. A take-up loop 19 is provided in the newly formed wire 18 with the size of the loop being controlled by suitable upper and lower control elements 20 and 21 herein comprising a pair of conventional electric eye sensing devices responsive to a movement of the loop 19 into the sensing area of either of the devices to permit suitable control selectively of the nozzle 17 or of the speed of the wire through the apparatus. Such controls are well known and conventional in web fed art and require no further description herein.

The loop 19 is provided in a chamber 22 defined by a housing 2 3 including a liquid cooling jacket 24 extending thereabout to provide an initial cooling of the extruded wire 18 in space 22. Suitable means (not shown) may be provided for circulating a cooling liquid, such as water W, through jacket 24. For this purpose, an inlet 25 and an outlet 26 may be provided in the jacket at spaced portions thereof.

As discussed above, the invention comprehends the forming of the plated wire10 without the need for removing chemically altered surface portions of the wire as conventionally form on metal, such as aluminum, by their exposure to ambient air. Thus, housing 23 is further provided with an inlet 27 for introduction of an inert gas, such as nitrogen, helium, or carbon dioxide, etc., or a reducing medium, such as hydrogen gas, preselected to prevent chemical alteration of the surface of the metal wire 18. More specifically, the gas herein prevents oxidationvof the surface of the aluminum wire 18 as it passes through the drawing portion 13 of apparatus 11 to the plating portion 14.

The working of the extruded wire 18 may be eected by any suitable working method. Illustratively, the working of the wire 18 herein is effected by a drawing of the fines, together with a further housing portion 31, a second chamber 32, and together with a third housing portion 33, a third chamber 34. Means are provided for conducting the inert gas sequentially from chamber 22 through chambers 32 and 34. Thus, passages 35 may be provided in plate 30 to provide communication between chamber 22 and chamber 32 and passages 36 may be provided in plate 30 to provide communication between chamber 32 and chamber 34. An outlet 37 may be provided in housing 33 for conducting the inert gas therefrom, such as for recirculation through inlet 27 by suitable pump means (not shown).

The wire 18 is drawn through die 28 and about a pulley 38 in chamber 32 to the die 29. The further drawn wire leaving die 29 may pass with one or more turns about a second capstan 39 in chamber 34 and through a sealing baille 40 into a plating chamber 41 defined by a closed tank 42 of plating portion 14. Thus, during the working operations, the extruded wire 18 is maintained in an inert atmosphere at all times effectively precluding chemical change of its surface so that upon delivery thereof directly into the plating fluid 43 in chamber 41, the surface of the wire is suitable for plating directly thereon without need of chemical or mechanical surface treating steps. At the same time, the wire is worked to provide improved strength and other desirable metallurgical characteristics obviating the need for such working steps subsequent to the plating operation. Still further, the flow of the inert gas through the chambers 22, 32 and 34 may be correlated with the movement of the hot extruded wire 18 therethrough the effect a desirable cooling of the wire prior to the delivery thereof into the plating fluid 43. The flow of the inert gas may be coordinated with the cooling effect of the cooling jacket 24 as desired.

The plating apparatus 14 may comprise a conventional electroplating apparatus utilizing a direct current source 44 for suitably charging anode electrodes 45 in contact with the plating fluid, herein comprising a conventional copper plating liquid solution, and a cathode ground connection 46 to the wire. The plated wire 10 may pass from chamber 41 through a sealing bushing 47 mounted on the tank wall defining chamber 41, to pass around a capstan 48 to a spooling device 49 to provide the plated wire in suitable lengths as desired. To further minimize possible attack of the wire surface prior to the effective plating thereof, a vacuum pump 50 may be provided for maintaining the chamber 41 substantially oxygen free by withdrawing such gas from the chamber 41.

In illustrating the invention, a single wire 18 has been described as being carried through the respective forming steps. The invention further comprehends the concurrent forming of a plurality of such wire as by providing a plurality of extrusion nozzles 17 and drawing dies 28, 29 with concurrent plating of the resultant drawn wires in the plating apparatus 14. Further, while the invention has been described in connection with the forming of wire or tube elements, as will be obvious to those skilled in the art, it is adaptable for plating of any extruded element. Where the element is relatively rigid, the path of the extruded element may be rectilinear.

Further, the invention comprehends the provision of the extruded element directly from the extruder nozzle to the plating bath where working of the element is not required. However, in passing from the nozzle to the bath, the extruded element is maintained in an inert fluid atmosphere to prevent surface changes as discussed above, within the scope of the invention. While the invention has been described in connection with an inert gaseous fluid, it will be obvious to those skilled in the art that other suitable insert liquid fluids may be used as desired. Further, while the plating operation has been disclosed as an electroplating operation, as will be obvious to those skilled in the art, other plating methods, such as vapor deposition, may be employed within the scope of the invention.

While we have shown and described one embodiment of our invention, it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made within the spirit and scope of the invention as defined in the appended claims.

We claim:

1. The method of continuously forming a plated elongated aluminum element comprising the steps of: extruding aluminum into a fluid which is substantially inert relative to the extruded aluminum, said aluminum being extruded to define an elongated element; working the element while maintaining it in said fluid substantially preventing chemical alteration of the surface of said element; delivering the worked element directly from said fluid into a plating fluid whereby said extruded element is delivered thereto without prior exposure to ambient atmosphere; and causing the plating fluid to plate the element.

2. The method of claim 1 wherein said working step comprises a drawing step.

3. The method of claim 1 wherein said plating step comprises an electroplating step.

4. The method of claim 1 wherein said elongated element comprises a wire.

5. The method of claim 1 wherein a plurality of plated elongated elements a're concurrently similarly formed.

6. The method of claim 1 wherein said plating fluid plates the element with a metal.

7. The method of claim 1 further including removing free oxygen from the plating fluid during the last named step.

8. The method of continuously forming a plated elongated aluminum element comprising the steps of: extruding aluminum into a fluid which is substantially inert relative to the extruded aluminum, said aluminum being extruded to define an elongated element; delivering the said element directly from said fluid into a plating fluid whereby said extruded element is delivered thereto without prior exposure to ambient atmosphere; and electroplating said element with said plating fluid.

9. The method of claim 8 wherein said elongated element comprises a wire.

10. The method of claim 8 wherein a plurality of plated elongated elements are concurrently similarly formed.

11. The method of claim 8 wherein said plating fluid plates the element with a metal.

12. The method of claim 8 further including removing free oxygen from the plating fluid during the last named step.

13. The method of continuously forming copper plated aluminum wire comprising the steps of:

extruding wires of aluminum into an inert atmosphere;

drawing the extruded wires while in said inert atmosphere; and

directly copper plating the drawn wires.

14. The method of continuously forming copper plated aluminum wire of claim 13 wherein said wires are drawn while at high temperature.

References Cited UNITED STATES PATENTS 2,061,554 11/1936 Billiter 204-209 2,370,973 3/ 1945 Lang 204-28X 2,657,457 11/ 1953 Toulmin 117-107.2X 2,680,710 6/ 1954 Kenmore etal 204-28 2,762,115 9/ 1956 Gates 29-527.4X 2,871,171 1/1959 Atkinson 204-28X V3,060,053 10/ 1962 Carreker et al. 164-86X 3,481,390 12/ 1969 Veltvi et al 164--81X FREDERICK C. EDMUNDSON, Primary Examiner U.S. C1. X.R. 

